4,438 research outputs found
Comparative analysis of Mycobacterium tuberculosis pe and ppe genes reveals high sequence variation and an apparent absence of selective constraints.
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110619.pdf (Publisher’s version ) (Open Access)Mycobacterium tuberculosis complex (MTBC) genomes contain 2 large gene families termed pe and ppe. The function of pe/ppe proteins remains enigmatic but studies suggest that they are secreted or cell surface associated and are involved in bacterial virulence. Previous studies have also shown that some pe/ppe genes are polymorphic, a finding that suggests involvement in antigenic variation. Using comparative sequence analysis of 18 publicly available MTBC whole genome sequences, we have performed alignments of 33 pe (excluding pe_pgrs) and 66 ppe genes in order to detect the frequency and nature of genetic variation. This work has been supplemented by whole gene sequencing of 14 pe/ppe (including 5 pe_pgrs) genes in a cohort of 40 diverse and well defined clinical isolates covering all the main lineages of the M. tuberculosis phylogenetic tree. We show that nsSNP's in pe (excluding pgrs) and ppe genes are 3.0 and 3.3 times higher than in non-pe/ppe genes respectively and that numerous other mutation types are also present at a high frequency. It has previously been shown that non-pe/ppe M. tuberculosis genes display a remarkably low level of purifying selection. Here, we also show that compared to these genes those of the pe/ppe families show a further reduction of selection pressure that suggests neutral evolution. This is inconsistent with the positive selection pressure of "classical" antigenic variation. Finally, by analyzing such a large number of genes we were able to detect large differences in mutation type and frequency between both individual genes and gene sub-families. The high variation rates and absence of selective constraints provides valuable insights into potential pe/ppe function. Since pe/ppe proteins are highly antigenic and have been studied as potential vaccine components these results should also prove informative for aspects of M. tuberculosis vaccine design
On minimal non-PE-groups
No full textAbstractIf H is a subgroup of a finite group G, by HG denote the normal closure of H in G. G is called a PE-group if every minimal subgroup X of G satisfies NG(X) ∩ XG = X. The author proves that all PE-groups are solvable with the Fitting height at most 3 and classifies the minimal non-PE-groups
Assessment of the availability of agricultural residues on a zonal basis for medium- to large-scale bioenergy production in Nigeria
No full textThe major agricultural crops grown in Nigeria are millet, yam, cassava, sorghum, rice, groundnut and maize. In terms of area grown (2001-06) the cereals were dominant with sorghum being the major crop grown followed by millet, maize and rice. Agriculture residue availability was based on the 6 zones in Nigeria and included both field residues and processing residues. A number of different scenarios were evaluated whereby Scenario 1 looked at the total potential availability of field residues, Scenario 2 took account of existing uses while Scenario 3 looked at a collection efficiency of 50% of the residues available from Scenario 2. The total amount of agricultural residue available each year was 55.9 Tg per year which equates to a potential energy value of 657.01 PJ. Field residues were the most abundant feedstock available i.e. 38.4 Tg annually compared with 17.4 Tg from processing residues which equated to 452.33 and 204.68 PJ of potential energy respectively. A large proportion of field residue availability (85%) was in the 3 northern zones which represented in excess of 80% of the land area and cereal crops accounted for 88% of field residues available. When competing uses for field residues were included in the analysis under Scenario 2 then the total amount of field residue available was 21.2 Tg which equates to an energy potential of 248.78 PJ. Under Scenario 3 where a collection efficiency of 50% was used residue availability for medium- to large-scale bioenergy production was 10.6 Tg equating to an energy potential of 124.39 PJ. (C) 2012 Elsevier Ltd. All rights reserved
The impact of the EU neonicotinoid seed‐dressing ban on oilseed rape production in England
No full text[[alternative]]The Study of Acknowledgement of Risk Management on Perception of PE Teachers in Taoyuan Junior High Schools
No full text[[abstract]]The purpose of this study was to (1) explore the acknowledgement about physical activity risk management of junior high school PE teachers in Taoyuan, (2) compare PE teachers’ perception difference about risk management with different background (3) realize the strategy of risk management plan of PE teachers in junior high school. (4) finally build effective risk management plan for all PE teachers in junior high school.
One hundred and ninety two Taoyuan PE teachers served as the subjects of this study with the questionnaire of ” PE Teacher’s Perception of The Risk Management”. This study used descriptive statistics, t-test, and one-way ANOVA to analyze data. Besides, the research also chose seven PE teachers to do semi-structured interview, trying to understand risk management strategy of PE teachers. The results were listed as below:
1.The perception of risk management of physical teachers in junior high school, based on the importance, was: theory layer, practical layer, law layer, entity and application layer.
2.Significant difference was found in gender, practical layer, law layer and entity; while other factors showed no significant difference.
3.All the interviewees didn’t take action about risk management , but all of them agreed that risk management plan of physical activity is necessary. They suggested higher authorities ask junior high school to set risk management plan for physical activity, and become an evaluated item.
In conclusion of the research, the PE teachers in junior high school think it is important to execute a better physical activity risk management. Author suggested junior high school should set risk management plan for physical activity to get “zero risk” in school.
Veterinary science : humans, animals and health
No full textThis living book is a collection of open access materials bringing scientific papers to a humanities audienc
AQA GCSE PE
No full textUnlock your full potential with this revision guide which focuses on the key content and skills you need to know. With My Revision Notes for AQA GCSE PE, which covers the Short Course, Full Course and Double Award, you can: - take control of your revision: plan and focus on the areas you need to revise with content summaries and commentary from an expert author - show you fully understand key topics by using specific examples to add depth to your knowledge of PE issues and processes - apply PE terms accurately with the help of key words and definitions on all topics - improve your skills to tackle exam questions with self-testing and exam-style questions and answers
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